Effects of enriched Freshwater Rotifer with vitamin C, On Growth indices of Persian sturgeon (Acipenser persicus) larvae rearing

Acipenser persicus is the most important sturgeon species in the south Caspian Sea, showing high mortality during larval culture. The aim of this study was to use the freshwater rotifer, Brachionus calyciflorus to feed A. persicus larvae to improve survival rates and enhance resistance. Three experimental treatments were used in this study Treatment 1, similar to the feeding protocol of the hatchery was initially fed decapsulated cysts of artemia and then fed daphnia Treatment 2, was fed a mixed diet of decapsulated artemia cysts, daphnia and freshwater rotifers and Treatment 3, was fed freshwater rotifers enriched with vitamin C (ascorbic acid 6- palmitate). A total of 45 larvae were stocked in each experimental tank (100 l capacity) filled with 30 l of water. Three replicates were used for each experimental group. Larvae were fed at the rate of 30% of body weight per day for 8 days. Mean dissolved oxygen, pH and water temperature throughout the experimental period were 9.58±0.2 mg/l, 8.5±0.1 and 22.5±0.5 ºC, respectively. Results showed significant differences in specific growth rate (SGR), percentage weight gain (WG), feed conversion ratio (FCR), and condition factor (CF) of experiment treatment 1 and treatment 3 and survival ratio were significantly different among treatment 3 and other treatments. This study demonstrated that Brachionus calyciflorus is a suitable live food for larval feeding.